New OprHelper that uses numpy
Use new OprHelper. Change how OPRs are stored in the Event model.
Rename opr_json to oprs_json. Fix event manipulator and corresponding tests to use new oprs_json property
Use new opr format on event details pages
remove stray line
use optimized OPR algorithm
only calculate OPRs for quals matches
fix linking to team year in opr table
Don't include a match in OPR calculations if it has not been played.
Cleaner erroring of OPR solving
No longer returns 'm'
Move computation for number of teams outside helper function
generalize oprs_json to matchstats_json to potentially include DPR, CCWM, etc
Generalize matchstats_json to also store DPR and CCWM
cleaner way to determine opposing alliance color
Update task enqueuing links
rename to matchstats
Merge pull request #825 from fangeugene/opr

OPR Calculation. Fixes #301